The BisocketClientInvoker never reads from the control socket. Therefore, it might take a long time for it to notice that the control connection dies, causing confusion between the client and server (for example, the client may reuse a listener ID that the server considers extinct). By adding a ping reply mechanism, the client must both send and receive a ping for the connection to be known "good", which should help speed up the dead connection detection process.
Since this change is protocol-incompatible, it should be enabled by a configuration option. I'm using Bisocket.ENABLE_PING_REPLY = "enablePingReply" for this purpose.